使用Static类或Abstract类进行对象创建

Question

So I have a general question. Lets say I want to create car objects in this program I am writing and I have to create hundreds of this car object. Is it better to create a car abstract class and extend it when I make my car object(ie Toyota, Nissan, etc.) or could I use a bunch of static classes that hold the details of the specific object and use that in a general car object to make the Toyota or Nissan? I think the using the abstract method should be pretty self explanatory but here is an example of the second method:

public class CarNames {

public static String getCarName(int pCarIndex){

    switch (pCarIndex) {
    case 0:         
        return "Toyota";
    default:
        throw new Error("pCarIndex does not exist!");
    }
}

}

Which is used in this class to create the object:

public class Car{

    private int mCar_ID;//This indicates which Car to load
    private String mCarName;

public Car(int pCar_ID){
    mCar_ID = pCar_ID;
            mCarName = CarNames.getCarName(pCar_ID);
            //Do Stuff with collected parameters 
}

}

Let me know if something doesn't make sense. Thanks.

EDIT: The cars may have different parameters such as size, engine, etc. The reason I chose an abstract class is because I think it offers more flexibility than an interface, since I could add methods down the line.

Answer 1

Is it better to create a car abstract class and extend it when I make my car object(ie Toyota, Nissan, etc.) or could I use a bunch of static classes that hold the details of the specific object and use that in a general car object to make the Toyota or Nissan?

Neither. You have precisely one Car class and a file (eg, database) containing the details of a particular vehicle. You then create instances of that one Car class based upon the file contents.

The cars may have different parameters such as size, engine, etc.

Programmers for the past half-century have referred to this as "data". The less data you bake into your source code, the better.

Answer 2

I am going to take a stab at this... I am not sure if your goal in the end is ease of maintenance or memory or... I am going to guess that because this is an Android question your concern is with memory. Especially when you talk about 100's of objects.

My first thought the flyweight pattern it will allow those objects to share memory and have smaller footprints. But I am with the @CommonsWare answer... Part of what your are talking about is data. If I understand your question, your plan is to define all the the different parts of your car in code based on the cardId that doesn't sound very efficient. That sounds like data, whether it be xml or sqllite database.

You might be talking about Nissans which could end up as a type (class) extending the abstract class car, but the engine size, height, width, and gas mileage is all data.